Molecular diversity of indigenous arbuscular mycorrhizal fungi in three different agricultural regions of Turkey

Little is known about the distribution of arbuscular mycorrhizal fungi (AMF, phylum Glomeromycota) in the Turkish arable soils. In this study, we investigated AM fungal phylotype composition in the roots of 13 different plant samples from one site each of the East Black Sea, Mediterranean, and Central Anatolian regions of Turkey. Fifty-seven distinguished operational taxonomic units at 97% nucleotide sequence identity were recorded among 424 partial sequences of the nuclear ribosomal large subunit (LSU) RNA genes determined. Most of the new sequences were clustered within 10 well-resolved phyloclades of the order Glomerales. About half of the newly determined sequences lacked similar sequences in the public databases. In particular, all sequences from Camellia sinensis collected in the East Black Sea region had only 83–97% sequence similarity to known AMF species. The findings suggest that novel and endemic AMF species may exist in Turkish agricultural soils. The AM fungal community composition in the East Black Sea region was relatively simple and completely differed from those in the other two regions, presumably due to the low soil pH and host specificity. The AM fungal community compositions of the Mediterranean and Central Anatolian samples were broadly similar; however, some sequences related to Rhizophagus were found only in the Mediterranean samples. This reflects the trend that more diverse AM fungal communities are established in the Mediterranean region than the Central Anatolian region.